1. Field of the Invention
The present invention relates to an occluder for sealing off a section of a blood vessel.
2. Description of the Prior Art
In surgical procedures, it is often necessary to seal off a small section of a blood vessel. This need may arise in vascular surgery, including coronary artery by-pass operations in which a blocked portion of the artery is by-passed with another blood vessel so as to restore and insure adequate blood supply to the heart muscle.
In such an operation, a short segment of vein, usually taken from the patient's leg, is used. One end of this blood vessel is connected to the aorta, the major body artery supplying all parts of the body except the lungs. The other end of the vein is connected to the blocked coronary artery below the blockage. The term "anastomosis" refers to the formation of such a passage and by reason of the anastomotic connection between the aorta and the artery, a by-pass around the blockage is provided.
The standard operative technique for a coronary artery by-pass requires clamping off the aorta to terminate blood flow to all the coronary arteries. By-pass connection or grafting then proceeds. The grafting procedure often involves as many as three by-pass grafts and sometimes as many as four or five. It may thus become necessary to clamp off the aorta for an extended period of time. During this time, there is no blood supply to the muscular tissue, or myocardium, of the heart. This prolonged cessation of blood supply can only be deleterious to an already diseased heart. Such clamping off of the aorta may be responsible for the life threatening infarcts which occur in two to five percent of by-pass patients.